Macintosh Quadra Family Technical Overview

Overview

This page documents the Macintosh Quadra family based upon the 68040
based procesors. The first two computers in the Quadra lineage were the
Quadra 700 derived from the Macintosh IIcx and the Quadra 900 derived from
the Macintosh IIfx. Later the Centris 650 and the Quadra 800 platform along
with the Centris 610 platform. The Quadra 605 and Quadra 630 are a part
of the Entry Level architectures and is documented there. The Qudra 660av
and Qudra 840av are covered in the Audio/Visual architecture.

Linux/m68k (macLinux) Notes

Generally Linux/m68k runs on any MC68020 with an external MC68551
PMMU (Paged Memory Management Unit) processor. Other processors after the
MC68020 have a built-in MMU (Memory Management Unit) with exception
of the MC68EC030 and other EC processors which cannot work
with Linux/m68k. It is good to have an FPU (Floating Point Unit) or math
co-processor as it is slow to use an emulator and difficult to configure.
Commonly, MC68881 math processor is used with the MC68020
and the MC68882 is used with the MC68030. The newer MC68040
contains a built-in math coprocessor. The MC68LC040 does not have
the built-in math coprocessor.

Linux/m68k has the ability to run on any Quadra computer and is currently
able to boot with a look in prompt on several machines. The Centris
610 and some models of the Quadra 610 contain the MC68LC040
processor which does not have a functional FPU or math coprocessor. For
these machines will need to replace MC68LC040 with a normal MC68040
processor or use a software FPU emulator.

Currently the Quadra 900 and Quadra 950 does not have the needed support
to get this machine to work properly. There are two IOP6502 ICs which control
the floppy/serial and adb. Without public documentation, keyboard, mouse,
floppy, and serial may not function.

Components

The following is a list of the components that make up the capabilities
of the Macintosh II Family line:

ADB (Apple Desktop Bus) is a bus for supporting up to 7 different
devices daisy chained onto each other. There are 16 addresses, and multiple-devices
like a trackball and a mouse can connected and utilized.

SCSI (Small System Interface) is built-in all Macintosh computers.
The Macintosh Quadra family uses the 53C96 chipset which supports 32bit
transfers.

Enchanced ASC (Apple Sound Chip) supports 8 bit stereo audio
output which made Macintosh famous for their sound capabilities until the
arrival of SoundBlaster in the open PC Clone market.

DAFB (Direct Access Frame Buffer) - This is the video buffer
in the Macintosh Quadra series which includes its own VRAM.

Ports

The Macintosh Quadra series contains the following ports:

1 RCA Streo input (Macintosh Quadra 900/950 only)

1 sound 1/8" microphone (8bit mono)

1 sound 1/8" jack (8bit stereo)

1 or 2 ADB ports for mouse and keyboards,

1 Printer Port (RS422 8 mini-din)

1 Serial (RS232 8 mini-din)*

1 SCSI-1 port (DB25)

1 RGB Video port (DB15)

1 AAUI-15 (Apple AUI) Ethernet

* This port is incompatible
with the familiar RS232 PC Serial port as it does not contain the missing
9th pinout. Most modem below 2.88K will work. Also note that the SCC chipset
uses a different style of communication familiar in the PC clone world.

Apple Related Developer Docs

These pages were created to illustrate the basic
machine information of the Macintosh II Family as a service to the MacOS
and Linux/m68k community. I would deeply appreciate any suggestions people
may have regarding additional information they would like to have added.
Email darknerd@mailexcite.com.